Induction type bolt heater

Abstract

The utility model discloses an induction type bolt heater which comprises an induction body, an electrode assembly, a drainage assembly and a temperature sensor. The drainage assembly is connected between the induction main body and the electrode assembly; the drainage assembly comprises a water inlet flow channel and a water outlet flow channel which are isolated from each other, and a water inlet and a water outlet which are respectively communicated with the water inlet flow channel and the water outlet flow channel are formed in the electrode assembly; a cooling channel for cooling water to circulate is arranged in the induction main body; the water inlet runner and the water outlet runner are respectively communicated with two ends of the cooling channel; the temperature sensor is attached to the outer surface of the induction body. According to the induction type bolt heater, the electromagnetic induction heating principle is utilized, bolt holes are heated, operation is easy, the heating speed is high, heating is even, the bolt dismounting efficiency is effectively improved, and the labor cost is saved.

Description

Technical Field

[0001] The utility model relates to the technical field of electric heating, in particular to an induction type bolt heater. Background Art

[0002] At present, large-diameter bolts of steam turbine high-pressure cylinders, low-pressure cylinders and various valve bodies in power plants mostly use hot-tightened bolts. This type of bolt needs to heat the bolt body during disassembly and assembly. The working principle of hot-tightened bolts is to heat the bolts, tighten the nuts after the bolts are elongated, and during the cooling process, the bolt body will shrink due to the decrease in temperature. Due to the mutual compression between the bolts and the nuts, the bolts cannot return to their original length after cooling. The bolts are in a stretched state, generating pre-tightening force. Under existing technical conditions, flame heating and resistive electric heaters can be used to heat the bolts, but the above two heating methods have certain limitations in heating speed.

[0003] Bolt heaters are important auxiliary tools for the installation and removal of large bolts, especially on large equipment in nuclear power plants. In order to achieve the required preload of the bolts, electric heaters are needed to heat the bolts to make them elongate, and then tighten the nuts according to the nut rotation arc length, nut angle or absolute elongation of the bolts. General bolt electric heaters are usually single-head electric heating tubes with metal shells. It is most common to use single-head electric heating tubes as the heating components of bolt electric heaters, and the heating effect is also good. However, the heating temperature of the single-head tube is not high and the heating time usually exceeds 15 minutes, which cannot meet some occasions that pursue efficiency. In particular, the single-head electric heating tube with a metal shell needs to be closely matched with the inner wall of the bolt hole when heating to achieve the maximum heating effect, but its matching clearance is small, and the bolts are easily stuck in the inner hole of the bolt and cannot be pulled out when heated, which poses a great safety hazard. When the insertion hole of the bolt heater is small and the heating temperature is required to be high, the ordinary single-head tube with a metal shell cannot meet the requirements.

[0004] Based on the above problems, there is an urgent need for an electric bolt heater with fast heating speed, safe and reliable use, convenient operation, reliable principle and good safety performance. Utility Model Content

[0005] The technical problem to be solved by the utility model is to provide an induction bolt heater.

[0006] The technical solution adopted by the utility model to solve the technical problem is: to provide an induction bolt heater, including an induction body for inserting into a bolt hole, an electrode assembly, a drainage assembly and a temperature sensor;

[0007] The drainage component is connected between the induction body and the electrode component; the drainage component includes a water inlet flow channel and a water outlet flow channel that are isolated from each other, and the electrode component is provided with a water inlet and a water outlet that are respectively communicated with the water inlet flow channel and the water outlet flow channel;

[0008] The induction body internally has a cooling channel for the circulation of cooling water. The cooling channel is U-shaped and both ends are located inside the end of the induction body connecting the drainage component; the water inlet flow channel and the water outlet flow channel are respectively communicated with both ends of the cooling channel; the temperature sensor is attached to the outer surface of the induction body.

[0009] Preferably, the induction body includes two metal tubes that are spaced and relatively cooperated. The first ends of the two metal tubes are connected and communicated, so that the internal channels of the two metal tubes form the cooling channel; the drainage component is connected to the second ends of the two metal tubes.

[0010] Preferably, the induction body further includes an electromagnetic shielding material and an electromagnetic enhancement material filled in the space between the two metal tubes along the axial direction of the metal tubes; the axial section where the electromagnetic shielding material is located forms a non-heating area, and the axial section where the electromagnetic enhancement material is located forms a heating area.

[0011] Preferably, the electromagnetic shielding material includes at least one of a polytetrafluoroethylene plate, a silicate plate, a mica plate, and an asbestos plate; the electromagnetic enhancement material includes at least one of a manganese-zinc ferrite, a neodymium-iron-boron magnetic core, and a samarium-cobalt magnetic core.

[0012] Preferably, the drainage component includes a first drainage pipe and a second drainage pipe that are arranged in parallel and cooperated. The water inlet flow channel is formed in the first drainage pipe, and the water outlet flow channel is formed in the second drainage pipe;

[0013] The electrode component includes a first electrode seat and a second electrode seat; the first electrode seat is connected to the end of the first drainage pipe far from the induction body, the second electrode seat is connected to the end of the second drainage pipe far from the induction body, and the first electrode seat and the second electrode seat are isolated from each other.

[0014] Preferably, the first electrode seat and the second electrode seat are in contact with each other; the electrode component further includes an insulating gasket and at least one set of insulating fasteners;

[0015] The insulating gasket is disposed between the first electrode seat and the second electrode seat, and the insulating fastener passes through the first electrode seat, the insulating gasket, and the second electrode seat to fasten the three into one body.

[0016] Preferably, the insulating gasket is a polytetrafluoroethylene plate, a silicate plate, a mica plate, or an asbestos plate.

[0017] Preferably, the drainage component is connected to the induction main body at an angle; the angle is a right angle, an acute angle or an obtuse angle.

[0018] Preferably, the inductive bolt heater further includes a high-temperature resistant insulating layer covering the outer surfaces of the induction main body and the drainage component.

[0019] Preferably, the high-temperature resistant insulating layer includes a high-temperature resistant insulating coating coated on the outer surfaces of the induction main body and the drainage component, and a high-temperature resistant insulating sheath covering the outside of the high-temperature resistant insulating coating.

[0020] The beneficial effects of the present utility model: By using the principle of electromagnetic induction heating, heating of the bolt hole is realized. The operation is simple, the heating speed is fast, the heating is uniform, the efficiency of bolt disassembly is effectively improved, and the labor cost is saved. Description of the Drawings

[0021] The present utility model will be further described below in conjunction with the drawings and embodiments. In the drawings:

[0022] Figure 1 is a three-dimensional structural schematic diagram of an inductive bolt heater according to an embodiment of the present utility model;

[0023] Figure 2 is an axial sectional structural schematic diagram of the induction main body in an inductive bolt heater according to an embodiment of the present utility model;

[0024] Figure 3 is a radial sectional structural schematic diagram of an inductive bolt heater according to an embodiment of the present utility model;

[0025] Figure 4 is Figure 3 a schematic diagram of the magnetic field eddy current after the shown inductive bolt heater is powered on. Detailed Embodiments

[0026] For a clearer understanding of the technical features, objectives and effects of the present utility model, the specific embodiments of the present utility model will now be described in detail with reference to the drawings.

[0027] As Figures 1 to 3 shown, the inductive bolt heater of the present utility model may include an induction main body 10, an electrode assembly 30, a drainage component 20 connected between the induction main body 10 and the electrode assembly 30, and a temperature sensor 40 disposed on the outer surface of the induction main body 10 for monitoring temperature.

[0028] Among them, the electrode assembly 30, the drainage assembly 20, and the induction main body 10 are connected in sequence and are electrically conductive. The induction main body 10 is used to be inserted into a bolt hole (a threaded hole that mates with a bolt or a hole on the bolt), and after being energized through the electrode assembly 30, a high-frequency pulse is formed to heat the bolt hole. The temperature sensor 40 is arranged on the outer surface of the induction main body 10 and can measure the temperature of the induction bolt heater itself and the bolt hole in real time to prevent overheating. The drainage assembly 20 and the induction main body 10 are internally connected and communicate with each other, and are used for cooling water to pass through for cooling and taking away heat.

[0029] In some embodiments, the induction main body 10 may include two metal tubes 11 that are spaced and cooperated relatively. Each metal tube 11 has opposite first and second ends. The first ends of the two metal tubes 11 are connected and communicated, so that the internal channels of the two metal tubes 11 are connected to form a cooling channel 100. The cooling channel 100 is in a U shape, and both ends of the U-shaped cooling channel 100 are located inside the end of the induction main body 10 connected to the drainage assembly 20. After the cooling water from the drainage assembly 20 enters from one end of the cooling channel 100, it flows along the U-shaped channel of the cooling channel 100 and then is output from the other end of the cooling channel 100.

[0030] In Figure 3 In the illustrated embodiment, the cross-section of each metal tube 11 is in a D shape, and the two metal tubes 11 are symmetrically cooperated, and the formed induction main body 10 is in a cylindrical shape. The interval between the two metal tubes 11 is in the diameter direction of the cylinder.

[0031] It can be understood that the induction main body 10 can be formed by connecting two independent metal tubes 11, or can be formed by bending a D-shaped tube.

[0032] The metal tube 11 is made of a highly conductive material such as gold, silver, copper, aluminum, etc., and the material is the aforementioned metal single substance or alloy material.

[0033] Furthermore, the induction main body 10 may further include an electromagnetic shielding material 12 and an electromagnetic enhancement material 13. The electromagnetic shielding material 12 and the electromagnetic enhancement material 13 are filled in the interval between the two metal tubes 11 along the axial direction of the metal tube 11. The electromagnetic shielding material 12 is used to weaken the magnetic field eddy current when the induction main body 10 is energized and working, and the electromagnetic enhancement material 13 is used to strengthen the magnetic field eddy current when the induction main body 10 is energized and working. Therefore, the axial section of the induction main body 10 where the electromagnetic shielding material 12 is located forms a non-heating area, and the axial section of the induction main body 10 where the electromagnetic enhancement material 13 is located forms a heating area. Through the formation of the heating area and the non-heating area, the heating requirements for different positions in the bolt hole are met.

[0034] The filling positions of the electromagnetic shielding material 12 and the electromagnetic enhancement material 13 can be adjusted flexibly. For example, the electromagnetic enhancement material 13 is relatively closer to the first end of the metal tube 11 than the electromagnetic shielding material 12, and the electromagnetic shielding material 12 is relatively closer to the second end of the metal tube 11 than the electromagnetic enhancement material 13. The filling of the above materials can be swapped according to actual needs.

[0035] Preferably, the electromagnetic shielding material 12 may include at least one of polytetrafluoroethylene board, silicate board, mica board, asbestos board, etc.; the electromagnetic enhancement material 13 may include at least one of manganese-zinc ferrite, neodymium-iron-boron magnetic core, samarium-cobalt magnetic core, etc.

[0036] One end of the drainage component 20 is connected to one end of the induction main body 10; the drainage component 20 is connected to the induction main body 10 at an angle, and the angle is a right angle, an acute angle or an obtuse angle. For example, as Figure 1 shown, the drainage component 20 is perpendicularly connected to the induction main body 10, and the formed induction bolt heater is in an L shape.

[0037] In some embodiments, the drainage component 20 is specifically connected to the second ends of the two metal tubes 11. The drainage component 20 includes a water inlet flow channel and a water outlet flow channel that are isolated from each other. The water inlet flow channel and the water outlet flow channel are respectively communicated with the two ends of the cooling channel 100. Thus, the cooling water enters the cooling channel 100 through the water inlet flow channel, flows along the cooling channel 100 to the other end portion, and then is output to the water outlet flow channel.

[0038] The drainage component 20 may further include a first drainage pipe 21 and a second drainage pipe 22 that are arranged in parallel and cooperate with each other. The water inlet flow channel is formed in the first drainage pipe 21, and the water outlet flow channel is formed in the second drainage pipe 22.

[0039] The first drainage pipe 21 and the second drainage pipe 22 are also respectively made of a conductive material, such as a metal material. The first drainage pipe 21 and the second drainage pipe 22 are adjacent and arranged side by side without contact.

[0040] The electrode assembly 30 is arranged at the end of the drainage component 20 away from the induction main body 10 and is used to connect to the power supply box. Corresponding to the water inlet flow channel and the water outlet flow channel of the drainage component 20. The electrode assembly is provided with a water inlet 301 and a water outlet 302. The water inlet 301 is communicated with the water inlet flow, and the water outlet 302 is communicated with the water outlet flow channel.

[0041] In some embodiments, the electrode assembly 30 includes a first electrode seat 31 and a second electrode seat 32; the first electrode seat 31 is connected to the end of the first drainage pipe 21 away from the induction main body 10, the second electrode seat 32 is connected to the end of the second drainage pipe 22 away from the induction main body 10, and the first electrode seat 31 and the second electrode seat 32 are isolated from each other (non-conductive between the two).

[0042] The first electrode base 31 and the second electrode base 32 are fitted together so that the electrode assembly 30 is a stable integral module. Each of the first electrode base 31 and the second electrode base 32 can be a polygonal block or sheet-like structure, etc.

[0043] To connect the first electrode base 31 and the second electrode base 32 into an integral module and prevent them from contacting and conducting electricity, the electrode assembly 30 further includes an insulating gasket 33 and at least one set of insulating fasteners 34. Among them, the insulating gasket 33 is disposed between the first electrode base 31 and the second electrode base 32, and the insulating fasteners 34 are inserted through the first electrode base 31, the insulating gasket 33, and the second electrode base 32 to fasten the three into one body. At the same time, the adjacent first drainage tube 21 and the second drainage tube 22 can also be fastened into one body.

[0044] The insulating gasket 33 is a polytetrafluoroethylene plate, a silicate plate, a mica plate, an asbestos plate, etc. The insulating fasteners 34 include, but are not limited to, ceramic bolts and ceramic nuts adapted thereto.

[0045] The temperature sensor 40 includes, but is not limited to, a thermocouple, and its probe end is located on the outer surface of the induction body 10. When the induction body 10 has a heating zone and a non-heating zone, the probe end of the temperature sensor 40 is located at the heating zone position. The temperature sensor 40 extends along the outer surfaces of the induction body 10 and the drainage assembly 20 so that the plug end of the temperature sensor 40 is outside the induction body 10, facilitating external connection to a monitoring device or a power supply box.

[0046] Furthermore, the induction bolt heater further includes a high-temperature resistant insulating layer 50 covering the outer surfaces of the induction body 10 and the drainage assembly 20, improving the insulation performance of the induction bolt heater and ensuring the safe and reliable use of the induction bolt heater.

[0047] The high-temperature resistant insulating layer 50 can further include a high-temperature resistant insulating coating 51 coated on the outer surfaces of the induction body 10 and the drainage assembly 20, and a high-temperature resistant insulating sheath 52 covering the outside of the high-temperature resistant insulating coating 51.

[0048] The high-temperature resistant insulating coating 51 can be formed by at least one of silicone oil, epoxy paint, polytetrafluoroethylene paint, etc. The high-temperature resistant insulating sheath 52 can be made of one or more of fiberglass cloth, mica tape, polytetrafluoroethylene tape, silicone rubber, polyimide film, etc.

[0049] The induction bolt heater of the present utility model utilizes the electromagnetic induction heating principle. The induction body 10 serves as an induction coil, and after being energized, it generates a magnetic field eddy current (as shown in Figure 4 ) to achieve heating of the bolt hole, and is applicable to heating and disassembly and fastening of turbine bolts, deep hole heating, etc., and has the characteristics of simple operation, convenient maintenance, and fast heating speed.

[0050] The above are only embodiments of the present utility model, and thus do not limit the patent scope of the present utility model. Any equivalent structural or equivalent process transformations made by using the content of the specification and drawings of the present utility model, or directly or indirectly applied in other related technical fields, are similarly included within the patent protection scope of the present utility model.

Claims

1. An induction bolt heater, characterized in that: It includes a sensing body for inserting into a bolt hole, an electrode assembly, a drainage assembly, and a temperature sensor; The drainage assembly is connected between the sensing body and the electrode assembly; the drainage assembly includes an isolated water inlet channel and a water outlet channel, and the electrode assembly is provided with a water inlet and a water outlet respectively connected to the water inlet channel and the water outlet channel; The sensing body has a cooling channel for cooling water circulation inside, the cooling channel is U-shaped and both ends are located inside the end of the sensing body connected to the drainage component; the water inlet channel and the water outlet channel are respectively connected to the two ends of the cooling channel; the temperature sensor is attached to the outer surface of the sensing body.

2. The induction bolt heater according to claim 1, characterized in that: The induction body comprises two metal tubes which are spaced apart and matched with each other. The first ends of the two metal tubes are connected and communicated with each other so that the internal channels of the two metal tubes form the cooling channel. The drainage assembly is connected to the second ends of the two metal tubes.

3. The induction bolt heater according to claim 2, characterized in that: The induction body also includes an electromagnetic shielding material and an electromagnetic reinforcement material filled in the interval between two of the metal tubes along the axial direction of the metal tubes; The axial section where the electromagnetic shielding material is located forms a non-heating zone, and the axial section where the electromagnetic reinforcement material is located forms a heating zone.

4. The induction bolt heater according to claim 3, characterized in that: The electromagnetic shielding material includes at least one of polytetrafluoroethylene board, silicate board, mica board and asbestos board; the electromagnetic reinforcement material includes at least one of manganese-zinc ferrite, neodymium-iron-boron magnetic core and samarium-cobalt magnetic core.

5. The induction bolt heater according to claim 2, characterized in that: The drainage assembly comprises a first drainage pipe and a second drainage pipe which are arranged in parallel and matched with each other, the water inlet channel is formed in the first drainage pipe, and the water outlet channel is formed in the second drainage pipe; The electrode assembly includes a first electrode seat and a second electrode seat; the first electrode seat is connected to the end of the first drainage tube away from the sensing body, the second electrode seat is connected to the end of the second drainage tube away from the sensing body, and the first electrode seat and the second electrode seat are isolated from each other.

6. The induction bolt heater according to claim 5, characterized in that: The first electrode seat and the second electrode seat are in contact with each other; the electrode assembly further comprises an insulating gasket and at least one set of insulating fasteners; The insulating gasket is arranged between the first electrode seat and the second electrode seat, and the insulating fastener is connected to the first electrode seat, the insulating gasket and the second electrode seat to fasten the three together.

7. The induction bolt heater according to claim 6, characterized in that: The insulating gasket is a polytetrafluoroethylene board, a silicate board, a mica board or an asbestos board.

8. The induction bolt heater according to any one of claims 1 to 7, characterized in that: The drainage component is connected to the sensing body at an angle, and the angle is a right angle, an acute angle or an obtuse angle.

9. The induction bolt heater according to any one of claims 1 to 7, characterized in that: The induction bolt heater also includes a high temperature resistant insulation layer covering the outer surface of the induction body and the drainage component.

10. The induction bolt heater according to claim 9, characterized in that: The high temperature resistant insulating layer comprises a high temperature resistant insulating coating coated on the outer surface of the sensing body and the drainage component, and a high temperature resistant insulating sheath wrapped around the outside of the high temperature resistant insulating coating.

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